Abstract
The bacterial cellulose (BC) is a biomaterial produced by many microorganisms that use carbon and nitrogen sources available in the culture medium. The standard medium HS, represents a high cost for the BC production on an industrial scale, because it is formulated with synthetic compounds. Industrial wastes are being explored for use in many biotechnological processes. Sugar cane molasses can be used as an alternative substrate for BC production. Molasses is a viscous liquid obtained as a residue from the manufacture of sugar or refining of raw sugar. In Brazil, molasses is the main by-product of the sugar industry, being produced in the proportion of 40 to 60 kilos per ton of processed cane. Thus, alternative culture media containing three samples (designated as A, B and C) of rawhide sugar cane molasses (R), molasses inverted by high temperature (IHT) and molasses inverted by acid and high temperature (IA/HT) as substrates, combined with different nutrients (glucose, yeast extract, peptone, citric acid and Na2HPO4) were used, resulting in 36 alternative media. The results obtained showed that the best cost and yield was reached by the alternative medium formulated with 15 g/L of rawhide molasses (sample B), 5 g/L glucose, 1.5 g/L acid citric and 2.7 g/L Na2HPO4, without any nitrogen source addition (medium 3), which demonstrated 52, 59 and 65% in dry, hydrated mass and yield, respectively, when compared to the standard HS medium. The use of sugar cane molasses can be an attractive and alternative option to reduce the costs for producing BC for industrial use. The results obtained favor researches that aim not only at industrial applications of BC at a reduced cost, but also the lower environmental impact in terms of pollution load and energy consumption caused by the use of vegetable cellulose and by the disposal of industrial waste.
